The Tenth Doctor and Donna Noble travelled to Calcutta in 1947. According to the Doctor, it was at the heart of the strife caused by the British Raj's failure to respond to a famine in the subcontinent in 1946. When the British didn't act to safeguard the people, Indians revolted and demanded independence. However, since the people of India were of many different faiths, the country was immediately plunged into a kind of religious civil war. Calcutta was at the front lines of this faith-based struggle — something which the Tenth Doctor and Donna observed at close range. (PROSE: Ghosts of India)

The details given in Ghosts of India are not entirely historically accurate. The independence-triggering famine was not in 1946, but rather in 1943. However, the implication of Partition inherent in Ghosts of India, and Calcutta's tumultuous place in it, is more or less "correct" when compared to real life events in 1947.